West Pacific/2015/11W/Archive/10
Public advisory TROPICAL STORM NANGKA PUBLIC ADVISORY NUMBER 10 WIKI-HURRICANES FORECASTING CENTER 6:00 AM JST MON JUL 06 2015 ...TROPICAL STORM NANKA SLIGHTLY STRONGER AS IT CONTINUES WEST... SUMMARY OF 6:00 AM JST...21:00 UTC...INFORMATION ------------------------------------------------------------------- LOCATION...11.7N 160.7E CENTER POSITION CONFIDENCE: MEDIUM ABOUT 375 MI...605 KM NNE OF PALIKIR, MICRONESIA MAXIMUM SUSTAINED WINDS...55 KT...65 MPH...100 KM/H MINIMUM BAROMETRIC PRESSURE...986 MB...29.12 INCHES PRESENT MOVEMENT...W AT 10 KT...12 MPH...19 KM/H DISCUSSION AND 48-HOUR OUTLOOK --------------------------------------------- At 6:00 am JST, the center of Tropical Storm Nangka was situated near 11.7N, 160.7E, or about 375 miles (605 kilometers) north-northeast of Palikir, Micronesia. Maximum sustained winds were 55 knots (65 mph, 100 km/h), with higher gusts. The minimum barometric pressure was 986 millibars (hPa; 29.12 inHg), and the cyclone was tracking west at 10 knots (12 mph, 19 km/h). Environmental conditions are expected to remain conducive for steady to perhaps rapid intensification throughout the forecast period, and indications are that Nangka will become a powerful typhoon over the West Pacific in the coming days. NEXT ADVISORY ------------------- Next complete advisory at 12:00 pm JST. $$ Forecaster TAWX14 Discussion TROPICAL STORM NANGKA DISCUSSION NUMBER 10 WIKI-HURRICANES FORECASTING CENTER 6:00 AM JST MON JUL 06 2015 Tropical Storm Nangka has strengthened some this evening. Although there has been little change in the presence of the cyclone on conventional satellite images, a series of microwaves passes indicate that a closed mid-level eye exists with a partial eyewall in the lower levels. Recent satellite intensity estimates were T3.0/45kt from SAB, T3.3/51kt from UW-CIMSS ADT, and T3.5/55kt from JTWC. However, given the improved presentation of the inner core compared to earlier this morning, the initial intensity has been raised to 55kt. Nangka is currently moving swiftly westward under the influence of a strong mid-level ridge across the northern West Pacific. This motion is expected to gradually turn west-northwestward over the next several hours as the anticyclone retreats northeast somewhat. By the latter stages of the forecast period, a trajectory just south of northwest is expected to take hold as a mid- to upper-level trough near Japan erodes the western extent of the mid-level ridge. On its current track, Nangka is expected to pose a threat to the northernmost Mariana Islands, and residents there should monitor the progress of the system closely. Water vapor animations indicate that the upper-level pattern is becoming favorable for substantial intensification, with an impressive equatorward outflow channel. Coupled with increasing sea surface temperatures and ocean heat content over the next few days, the stage is all but set for Nangka to become a powerful tropical cyclone. One limiting factor may be the presence of mid-level dry air, especially across the system's western quadrant, but this should be effectively mixed out once an inner core becomes established. All reliable model guidance remains in good agreement, and the intensity forecast is not too different from the previous one. INIT 05/2100Z 11.7N 160.7E 55 KT 65 MPH 12H 06/0600Z 11.8N 158.6E 60 KT 70 MPH 24H 06/1800Z 12.6N 156.5E 70 KT 80 MPH 36H 07/0600Z 13.7N 154.4E 80 KT 90 MPH 48H 07/1800Z 14.9N 152.2E 90 KT 105 MPH 72H 08/1800Z 17.4N 148.4E 105 KT 125 MPH...APPROACHING NORTHERN MARIANA ISLANDS 96H 09/1800Z 20.1N 144.8E 115 KT 130 MPH 120H 10/1800Z 22.1N 142.2E 125 KT 145 MPH $$ Forecaster TAWX14